Thirst thing that came to my mint is netstat. Second is nmap.
I'm not sure if those programs are good for that. My guess is that with nmap I can do almost everytung.
What I would like to check is (firefox as an example)
- If I don't run firefox is it sending or receiving something and if yes then what it is?
- If I run firefox and not use it. Let's say browser is open in background and I use libreoffice.
- And last case. After system boot and user login. If I don't do anything. Do not run any software (exept for terminal or gui software for net monitoring). I would like to know if there is any process or program that is using network connection in the background